Combination water-tube and fire-tube boiler.



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APPLICATION FILED AUG.25, 1915.

COMBINATION WATER TUBE AND'FIRE TUBE BOILER.

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APPLICATION FILED AUG.25 1915.

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WILLIAM ROHRBACHER, F ERIE, PENNSYLVA`NIA.

GOMBINATON WATER-TUBE .AND FIRE-TUBE BOILER Specification of Letters latent.

\ Patented Mar. l?, 19H5.

Application filed August 25, 1915. Serial No. 47,315.

1 To all whom t may concern:

tube and watertube boilers,V and has o-rone of its objectsV the provision of a boiler in i .which the travel of the water circulation is position instead of Qin the same direction as the flue gases, and

in which a positive circulation of the water is assured. l

Another object of the invention is the provision of a combined fire ltube and water tube .boiler so constructed' as to Aassure a maximum evaporation due to the utilization of all the heat, a resultant drier steam and consequent increased capacity boiler without increasing the size of the boiler.

A still further object of the invention is the provision of a combined fire tube and water tube boiler so constructed as to provide, in the boiler, lthe advantage of economizer, rendering the employment of an economiser unnecessary.

Still another object oic the invention is to yprovide a boiler bi the type described in which thel tubes discharge in horizontal position as is the general. practice iny water tube boilers, thereby reducing to .a minimum the chances of a slug of water in the steam line.

Still another object is to provide a boiler of the type described having by reason of the construction and arrangement, a large combustion chamber, and a large steam space, desideratuins much sought after in boiler construction, and also a construction which results in the elimination of all dead water in the boiler.

lStill another ob'ect of the invention is to provide a boiler in which the number of re pair' parts are reduced to a minimum, in

which all parts are readilyaccessible, and

which can be fixed with diffe-rent forms or styles of furnace as may be desired; furthermore, a boiler in which all parts which come in contact with the tire or furnace gases are covered with water, assuring same against burning.

in a vertical" or inclined wWitlithe above general and other specific g objects in view whichwill hereinafter more fully lappear 'as the invention is more fully described and claimed, the invention con.- .60

sists in the novel construction, combination and arrangement of 'parts as will appear 'from the detail descriptionk of a practical and preferred embodiment of the invention as disclosed in the accompanying drawings forming a part of this specication andI wherein like numerals of reference are used to designate like parts throughout the. diierent views in which Figure 1 is a central vertical sectional 70 view of a boiler in accordance with my in- .l

vention, the boiler being broken away, as is `also one of the firing furnaces or ovens, and

connection with the stack or iue being omitted. Fig. 2 is a horizontal sectional 75 view of a boilerA in accordance with this invention, looking toward the furnace or ovens on line II-II of Fig. 1. Fig. 3 is a view in elevation on a reduced scale showing the connection with the stack or flue, the lat- 8.0

ter being broken away, and Fig. 4t is a view in plan partlybroken away .and'partly in j section, on the saine scale as Fig. 3, showing a circular furnace for r'ing in. lieu of' the Dutch ovens shown in Figs.V 1. and 2.

lThe embodimentot `the invention' as herein shown comprises an upper or top drum 5 mounted in the top of the boiler setting 6 l and extending above said setting. and .down

intorthe chamber within the boiler setting. 90

This upper drum 5 is connected to a bottom drum 7 bythe largelcentrally disposed tube 8 that is riveted or otherwise secured at its upper end to the lower end of the top drum 5, and at its lower end tothe upper end of 95 the bottom drum 7.

An extension 9 is secured, as by tap bolts or studs onto the lower end of the tube 8 and'eXtends downwardly some distance into the bottonidrum Tfor the purpose of car- 10@ rying the water circulation wellgtowai'dthe bottom of the drum 7. This tube extension 9 is preferably made in three parts and bolted' together vertically so that it can be easily taken `out for repairs or for cleaning l@ the bottom of drinn 7. Holes 10 near the top of the extension tube Q'are provided for the purpose of allowing'any vapor that niay accumulate near the top of druni 7 to escape into the extension 9 and tube 8, thereby 11i? preventing the formation of a steam pocket in' the top of ydrum 7.

Water tubes 11, are arranged in'spaced rfows'around the circumferenceof the projecting lower end of the top drum and the. upper portion of the bottom drum 7 .to'fwhich*drums the respective ends of said tubes are secured .and ythe connections made steam and water tight in the usual manner.

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.. 'the' top drum 5.

vThe water tubes 11 surround a central baiiie wall 12, said tubes being located in the space 14; between the baille wall 12 and the boiler setting 6, the central baHle being supported upon a cast iron shoe 15 thatv eX- tends aroundtheupper end of the bottom drum 7.

The fire tubes y16 are all arranged in vthe as to the nature or form of furnaceemployed in connection with the boiler improvement. The4 bottom drum 7 issupported by lugs 19 riveted or otherwise secured to the outside of the drum on each quarter.

2O representsa 21 represents the stack or outlet flue. `A space 21 is provided at'one side to ltake out and replace tubes and also to enable cleaning of the combustion chamber. This space in practice is at'the point where the drums are joined by butt straps, through which the tubes cannot be extended.

In operation, furnace gases from the furnace or furnaces passes up the space 14 between walls 6 and 12 to the top drum 5 and then down the space between the baffle wall 12--and1 large center tube 8, through fire tubes .16 tothe usual .tunnel or space (indicated at 22, Fig.' 3. under the boiler) and thence to .the stack or chimney. Thus, at .the same time, the water contained withinthe drum 7 is being subjected to the zation of all the heat units.

heating action of the tubes 16, and the water in tubes 11, drum 5 and tube 8 is being sub- A jected to the heating 'action of the furnace gases as the latter circulate through the boiler to the outlet at the bottom of the same'.

By this construction I obtain a positive circulation of the water, traveling in the Vsame direction as therlue gases and a resultant'greater evaporation due to the utili- The lire tubes arranged in the bottom drum -answer the same purpose as an economizer rendering the use -of an economizer unnecessary I desireto call attention tothe fact that with i 'the construction shown and described a very large combustion chamber is provided, and also a large liberating space, as, all the water perforated baille plate in tubes discharge around the circumference of the top drum. Owing to the fact thatA the water tubes extend horizontally at their upper ends and thus discharge the water horizontally instead of vertically as is usual in water tube -boilers the chances of getting a slug of water in thefsteamv line is reduced to a minimum. The top drum provides a large ysteam space, and no dead water obtains, as the circulation is carried to the `bottom of the lower drum;

The device is extremely simple in its construction, and all that isneeded to erect at the plant is a flue expander and beading' tool, as'all rivets are driven in the shop. This renders the boiler easy to ship and handle. No bracing is requiredfor the top drum and but a small space in the bottom drum need be braced. All. parts that come in Contact with. the fire or furnace gases are covered with water thereby reducing the chances of required'repairs to the minimum. It to be noted that the water tubes Iare of different lengths, but of the same shape while' the `fire tubes are all of the-same size and shape,` so that there are the smallest possible number of repair parts required.

The embodiment here shown is of a furnace of circular form and described accordingly. It is to be understood however that I do not so limit myself as to shape but that' this and other features may be altered and changed without departing from the spirit and scope of the invention as disclosed and claimed,

What I claim is 1. In a combined water tube and fire tube boiler, a top drum and a bottom drum, 'a tubular member connecting the drums, a cylindrical baille wall supported at its lower end` on the lower drum and spaced at its Lipper end from the upper drum, water tubes `connecting said drums and spaced outwardly ofthe baiiie wall, and fire tubes eX- tending through the bottom drum and communicating at their upper ends with the chamber aorded by the baflie wall.

2. In a combined water tube and fire tube I boiler, a top drum and a bottom drum, a

vtubular member connecting the same, water tubes connecting said drums around the circumference, a baffle wall` positioned between said tubes and tubular member and extending substantially the entire lengths thereof, said tubes having curved upper end s leading into the top drum in a horizontal plane, and fire tubes inthe bottom drum positioned inwardly of the baffle wall. v

3.In a boiler of the type described, a top drum and a bottom' '.drum, a central combustion chamber between the drums and communicating at its upper end with a lateral combustion chamber, and watertubes con#v necting said drums arranged in said lat; eral chamber and in communication with Linnea v g the central chamber adjacent their upper ends, the tubes leading into the top drum in a horizontal plane.

4. In a boiler of the type described, a top drum and a bottom drum, a plurality of water tubes connecting the confronting ends of said drums around their circumference, a central tubular member connecting the drums, and an extension carried by said ,member extending downwardly into the bottom drum with the lower end thereef .disposed parallel to the lower end of the lower drum and spaced from the lower end thereof, and fire tubes in the lower drum surrounding said extension and communiv eating at their upper ends with the combustion chamber spaced inwardly of the baffle.

6. In a boiler of the type described, upperv and lower communicating drums, heat defiecting means extending from the lower drum to a point adjacent the upper drum,

and vconnecting `tubes -between the drums spaced outwardly of the heat delecting 'means 7. In a boilerof the type described, a top drum and a bottom drum, a tubular member connecting the confronting ends of said drums centrally of saidends, a bafie surrounding said member and extending upwardly from the lower end thereof to a point adjacent the upper end, water tubes lconnecting the drums, said tubes lying in the space between said battle and the boiler setting, an extension carried by thecentral connecting member and extending downwardly into said bottom drum, and tire tubes in thebottom drum around said extension and communicating at their upper ends with the chamber within the baiie.

In testimony whereof l aliiX my signature.

'WLLIAM BOHRBACHER. 

